Impulse measuring device



April 8, 1947.

e L 016/ I 17703 G. A. MORTON ETAL IMPULSE MEASURING DEVICE OriginalFiled Jan. 21, 1943 2 an H) Clem/7' 4- :w/rc'M/va anew/r 54 IN V EN TOR5. 6E0! A. MORE/V Y 8' Lea/5 E. FLO/2y Patented Apr. 8, 1947 IMPULSEMEASURING DEVICE George A. Morton and Leslie E. Flory, Princeton,

N. J., assignors to Radio Corporation of America, a corporation ofDelaware )riginal application January 21, 1943, Serial No.

473,146, now Patent No. 1946. Divided and this 1945, Serial No. 571,880

Claims. (Cl. 177-9353) vention to the various circuits to be describedis the well known trigger circuit of the general type described in"Theory and Application of Vacuum Tubes, by Herbert J. Reich. In one ofits simplest forms, this trigger circuit includes two triodes in whichthe grid of the first triode is coupled to the anode of the secondtriode through a network comprising a parallel connected resistor andcapacitor, and the grid of the second triode is similarly coupled to theanode of the first triode through a similar coupling network. Thecathodes of both triodes are grounded, either directly, or throughsuitable cathode resistors. Grid and anode potentials are,

applied to the respective electrodes through separate resistors, Ifdesired, a gaseous discharge tube may be connected across one of theanode resistors to indicate circuit operation.

In operation, if a negative voltage is applied to the grid of the firsttriode, the anode current of the triode will be reduced and the anodepotential will become more positive. Due to the connection through thecoupling resistor, the grid potential of the second triode will becomemore positive, causing an increase in the anode current of the secondtriode, with a resultant decrease in the second triode anode potential.This decrease in anode potential will, in turn,

cause the grid potential of the first triode to become more negative.This action will continue until the anode current of the first triode iscut off. The first triode will remain cut oil, and the second triodewill remain conducting, until a positive potential is applied to thegrid of the first triode or a negative potential is applied to the gridof the second triode. In either latter in- .stance, the tube operatingconditions will be reversed and the first triode will become conductingand the anode current of the second triode will be cut off.

One of the features of the instant invention is the utilization of suchtrigger circuits in cas- 2,404,047, dated July 16, application January8,

cade arrangement, whereby a predetermined change in the polarization oractlvization of one triode of the trigger circuit will generate a pulseto trigger or activate a succeeding trigger circuit in the cascadearrangement. As many trigger circuits as desired may be connected incascade.

The present invention has for its principal object the provision of animproved apparatus and method of operation whereby predetermined numbersof electrical impulses are transmitted from a continuously operatingconstant frequency source to an electronic computer or other utilizationdevice.

The invention will be better understood from the following descriptionconsidered in connection with the accompanying drawings and its scope isindicated by the appended claims.

Referring to the drawings:

Figure l is a block diagram of a preferred embod ment of the invention,and

Figure 2 is a wiring diagram of this embodiment.-

Fig. 1 provides a general means for deriving a predetermined number ofstepping pulses in rapid succession upon application thereto of aninitial starting voltage.

A source of oscillations 80, of Waveform 8|, is connected through apulse shaping circuit 82 to provide sharply defined negative pulses 83.These negative pulses are then applied simultaneously, through a switchs4, to a delay circuit 84 and a switching circuit 85, such as amultivibrator.- The switching circuit, in response to the initialnegative pulse applied thereto, provides a positive bias potential tounblock an amplifier 86. After the amplifier 86 is unblocked, thedelayed pulses are applied through the delay circuit 84 to the amplifierinput circuit. The output circuit of the amplifier is next applied to anelectronic counter 81, which may be of the general type described in thecopending U. S. application of Leslie E. Flory, Serial No. 467,032,filed November 28, 1942, in which any predetermined number of pulsesapplied thereto willprovide a control potential when the counter isfilled.

When the desired number of pulses are counted.

the control potential derived from the counter is applied to the amplfier to bias oft the amplifier anode current. Thus a predeterminednumber of pulses may be delivered to a load circuit connected to theamplifier output circuit. The number of pulses may be controlled bychanging the electronic counter as described in the copending Floryapplication. The circuit may be cleared for a succeeding operation bydisconnecting or electronic counter. to restore the counter to anypredetermi'nedinitial count. it should be under- As hereinafterexplained in connection with Fig. 2, the delay circuit 84 may beaconventional.

slideback trigger circuit having grid resistors of different values suchthat it has only one stable operating condition. The values of thesegrid put the amplifier 88 in a conducting condition,

but (2) returns to its stable operating condition before the second ornext successive pulse applied irom the pulse shaper 82. Each time theslideback trigger circuit returns to its stable operating condition, thesecond control grid of the amplifier 86 is made more positive and acounting pulse is applied to the counter 81.

Fig. 2 provides a specific circuit for the operation generally describedin Fig. 1. The oscillator 88 is of the conventional M type. Its outputcircuit is connected through the conventional pulse shaping circuit 82to provide the discrete negative pulses 83. The negative pulses are thensimultaneously applied to key the switching multivibrator 85 which is asymmetrical trigger circuit of the type described heretofore, and to keythe slideback trigger circuit 84 which provides the required delay forthe pulses applied to the second control electrode of the amplifier tube86. A positive bias potential is derived from the switchingmultivibrator 85 which has its current conductivity changed from itsleft to its right side in response to actuation thereof by the initialnegative pulse. This positive bias potential is applied to the firstcontrol electrode of the'amplifier tube 86 to unblock the tube foramplification of the delayed pulses. The minimum delay time of theslideback trigger circuit 88 must be sufiicient to allow the switch 85to put the amplifier 88 in a conducting'condition. This is necessary toprevent the delayed pulse being applied to the amplifier before theamphfier isin condition to pass it.

The maximum delay time must be short enough to allow the delay circuit84 to resume its normal stable operating condition before the nextsucceeding pulse is applied. Thus each time the delay circuit 84 returnsto its stable operating condition with its left side conducting, a pulseis applied through the amplifier 88 to the counter 81.

The anode circuit of the amplifier 88 is connected to the electroniccounter 81 which includes the trigger circuits 88, 89, 90, 9|, 82connected to provide a control potential when a predetermined number ofpulses have been counted. In the particular circuit disclosed, operationof the switch 83 will provide a control pulse for either six or fourteenapplied pulses from the amplifier 86. The control potential is derivedfrom the movable element of the switch s3 and applied to the firstcontrol electrode of the amplifier 86 to block the tube anode current.The number of pulses required for the control potential depends upon theparticular trigger circuit connected to the movable elements oftheswitch s3. The predetermined number of pulses are then derived from theamplifieranode circuit and applied to the utilization circuit.

The pulse generator may be cleared by opening the switches sl and s5.Opening the switch s4 removes the source of oscillations from thecounting circuit, 'while opening the switch s5 changes the bias on alltrigger circuits oi. the

stood that the essential difference between the counter of Fig. 2 andthe counter circuit disclosed in the copending Flory U. S. applicationreferred to heretofore, is that in the instant device the initial cbuntis provided by reversed bias means in one or more predetermined triggercircuits, (in this instance, trigger circuit 89), while feedback meansare provided in the copending application.

All trigger circuits may be cleared, after each multiplying operation iscompleted, by applying a high negative control electrode biassimultaneously to allbinary I tubes in the manner which is described,for example, in the copending application mentioned heretofore, or byremoving the grid bias from the binary 0 tubes.

It should be understood that the particular circuits described aremerely illustrative 01' one means for accomplishing the invention. Manyof the individual circuits may be modified, and the coupling and controlcircuits varied in accordance with accepted engineering practice,without deviating from the spirit and scope of the invention.

We claim as our invention:

1. A circuit for generating a predetermined number of voltage pulseswhich includes a source of oscillations, a blocking amplifier, meansresponsive to said oscillations for initially unblocking said amplifier,means responsive to said oscillations for delaying said oscillationsuntil said amplifier is unblocked and for applying said delayedoscillations to said amplifier, an electronic counter, means forapplying said delayed and amplified oscillations to actuate saidcounter, means for deriving a control potential from said counter when apredetermined number 0! oscillations have been counted thereon, meansfor applying said control potential to block said amplifier, and meansfor deriving said pulses from said amplifier.

2. A circuit for generating a predetermined number of voltage pulseswhich includes a source of oscillations, a blocking amplifier, meansmcluding a trigger circuit responsive to said oscillations for initiallyunblocking said amplifier, means responsive to said oscillations fordelaying said oscillations until said amplifier is unblocked and forapplying said delayed oscillations to said amplifier, an electroniccounter, means tor applying said delayed and amplified oscillations toactuate said counter, means for deriving a control potential from saidcounter when a predetermined number or oscillations have been clllationsfor delaying said oscillations until said amplifier is unblocked and forapplying said delayed oscillations to said amplifier, an electroniccounter, means for applying said delayed and amplified oscillations toactuate said counter,

means for deriving a. control potential from said counter when apredetermined number of oscil'-' lations have been counted thereon,means for applying said control potential to block said ampiiner, andmeans for deriving said pulses from counter and said unblocking meansafter each said amplifier. derivation of said pulses.

4. A circuit for generating a predetermined number of voltage pulseswhich includes a source GEORGE A. MORTON. of oscillations, a blockingamplifier, means in- 5 LESLIE E. FLORY. eluding a trigger circuitresponsive to said oscillations for initially unblocking said amplifier,REFERENCES CITED trigger circuit delay means resmnsive Said The followinreferences are oi record in the oscillations for delaying saidoscillations until me of this paint: said amplifier is unblocked and forapplying said 10 delayed oscillations to said amplifier, an elec-UNITED'STATES PATENTS tronic counter comprising a plurality of triggerNumber Name t circ it m n for pp ying said delayed and am- 2,373,134Massonneau Apr. 10, 1945' plifled oscillations to actuate said counter,means 2,153,235 K May 1 ,1939 for deriving a control potential from saidcounter 15 2,310,105 Michel b, 2, 1943 when a pretdeetermined number ofoscillations have 2,332,300 c k a t, 19, 1943 been coun d thereon, meansfor applying said control potential to block said amplifier, and FOREIGNPATENTS means for deriving said pulses from said amplifier. N m rCountry Date 5. Apparatus of the type'descrlbed in claim 1 20 485,703British May 24, 1938 including bias means for clearing said electronic355,705 British Aug. 24, 1931

